Musnad Abu Ya'la al-Mawsili 5:23

Sa'id ibn Abi al-Rabi' al-Samman narrated to us, Muhammad ibn Dinar al-Tahi narrated to us, Hisham ibn 'Urwah narrated to us, from his father, from 'Abdullah ibn al-Zubayr, from al-Zubayr, from the Prophet, peace and blessings of Allah be upon him: "One suck and two sucks do not make [marriage] unlawful, nor does one gulp and two gulps."